It is not possible to revert to an automatic style

Submitted by an unknown user

Description

Make a simple pie plot with at least two values. By default, there are two colors used, one for each value. Now, change the series back color. There is no way (at least I'm unable to find one) to revert to the default. All colors are the same for ever.

There are several possible solutions:

don't allow color changes when the vary-by-element flags is set;

add a button or a check box to revert to default;

check if the set value is the default after each change.

The third solution might be a bit tricky to implement. I prefer the second.
Any other opinion?